The spacing of the rails of a track of given gauge, supported by transverse ties, is constant along straight track sections but varies from one tie to the next at certain locations such as curves, junctions and switch points. It is therefore customary to use wooden ties for these nonlinear track sections which enable the proper positioning of mounting bolts according to measurements made in situ. thus with the precision necessary at such locations. Though the use of precast workpieces of prestressed concrete for railroad ties is generally desirable, it has been difficult heretofore to provide precast workpieces with inserts such as screw anchors in precisely predetermined positions.